A commonly used electronic packaging process is for electrical “daughter” modules, such as circuit boards or modules, to be plugged perpendicularly into respective connectors on a “motherboard”. The term motherboard is often used synonymously with the term backplane to describe a circuit board that contains general circuitry and connectors into which other circuit boards or modules can be plugged. The connectors provide both a physical mount and an electrical interconnect between the daughter boards (modules) and the backplane (motherboard). Usually the backplane is incorporated into a rack (or sub-rack) that may include a chassis or enclosure that surrounds and protects the circuit boards. The chassis may be supplied with guides such as slots and/or pins for guiding the boards into proper position for mating with the connectors on the chassis and further to support the daughter boards with respect to the enclosure or chassis.
Wedge-clamps heretofore have been provided on the edges of the circuit boards or modules as a means to securely hold the edges of the circuit boards in the slots in the chassis. Such wedge-clamps are typically located between one edge of the circuit board and a wall of a slot formed in the chassis. Tightening the wedge clamp forces the board to reference to the chassis slot rather than the (usually underlying) motherboard to which it may be connected. If the slots and motherboard connection are not accurately aligned relative to one another, the board will translate and/or bend and the connector will be stressed, creating a point of possible failure.
The problem is more acute when the circuits are packaged in module form. Typically such modules have a rigid cube-like housing, containing electronics circuitry mounted on one or more circuit boards. The module also has one or more connectors usually located along an edge of the module for electrical connection to a motherboard/backplane. The module includes guides, usually provided on opposite sides of the module, to fit into the slots in the chassis. The guide-slot alignment for locking the guides in place with conventional wedge-clamps requires that the module housing and the chassis slots be formed with relatively precise tolerances to obtain a proper fit and locking action. This increases the cost (in terms of time, labor and expense) of manufacture of such components.